Original vs Aftermarket vs Reconditioned - Plate Heat Exchangers

[SirLancelot]

Looking to open up a discussion - purely to learn / discover something new. The point of this thread is to explore the topic.

When a Plate Heat Exchanger (PHEx) is blocked - one obvious option is to clean out the unit (spirit of salts etc) & then refit.

What are members thoughts about compatible / aftermarket PHEx's.

I ask as I came across brand new (compatible/ aftermarket) units for around £30 whereas the manufacturer original unit is roughly £100 - more than three times the price!

Once a boiler is past it's warranty period - what are the disadvantages of using an aftermarket (over original) PHEx?

Does anyone have experiences in deploying/installing them?

Furthermore - what are members thoughts on reconditioned units? Which supplier would you trust to do the reconditioning safely & correctly?

 

[HERTS P&D]

Genuine parts all day long!

Lets say the boiler lasts another 3 years being used everyday, that works out at just over 9pence per day.

Andy

 

[ianmcd]

Furthermore - what are members thoughts on reconditioned units? Which supplier would you trust to do the reconditioning safely & correctly?

you cant recondition a plate heat exchanger, they simply clean them and call them reconditioned, just clean it yourself

 

[SirLancelot]

There are a variety of methods used to unblock and clean the plates. (This is part of exploring the topic):

Some use ultrasonic baths - with system descaler.

Others have custom rigs that essentially powerflush the plates.

One of the suppliers I talked too - does not use any chemicals of any kind whatsoever. They just use high pressure reverse flow to unblock the plates at very high temperatures.

What is curious to me is that if any chemical is to be used, is extremely important to use the right type of chemical & dosage, and to ensure that no residue remains at the end of the overall process.

I wonder if some of the chemicals used such as SOS - can corrode the metal plates inside (micro-bores) & a passage between the CH water and HW could develop over time. Surely this would be unhealthy?

 

[ianmcd]

There are a variety of methods used to unblock and clean the plates. (This is part of exploring the topic):

Some use ultrasonic baths - with system descaler.

Others have custom rigs that essentially powerflush the plates.

One of the suppliers I talked too - does not use any chemicals of any kind whatsoever. They just use high pressure reverse flow to unblock the plates at very high temperatures.

What is curious to me is that if any chemical is to be used, is extremely important to use the right type of chemical & dosage, and to ensure that no residue remains at the end of the overall process.

I wonder if some of the chemicals used such as SOS - can corrode the metal plates inside (micro-bores) & a passage between the CH water and HW could develop over time. Surely this would be unhealthy?

All the above cleaning methods are simply that, nothing is being re-conditioned

As for the plate pinholing and the two waters mixing , this is quite common under normal use, the system pressure will keep rising as the DHW passes into the primary water system

 

[gas112]

Twenty mins to clean them out with acid while your actually on the job why would you bother with another visit first time fix and happy cust

 

[ScottishGasMan]

There are a variety of methods used to unblock and clean the plates. (This is part of exploring the topic):

Some use ultrasonic baths - with system descaler.

Others have custom rigs that essentially powerflush the plates.

One of the suppliers I talked too - does not use any chemicals of any kind whatsoever. They just use high pressure reverse flow to unblock the plates at very high temperatures.

What is curious to me is that if any chemical is to be used, is extremely important to use the right type of chemical & dosage, and to ensure that no residue remains at the end of the overall process.

I wonder if some of the chemicals used such as SOS - can corrode the metal plates inside (micro-bores) & a passage between the CH water and HW could develop over time. Surely this would be unhealthy?

Most small plates are a mixture of stainless steel and copper, the copper is there to give them a little flexibility when there undergoing thermal stresses, you need to be careful cleaning them as incorrect or overly strong chemicals could corrode the copper and cause the plate to leak. Although there pretty sturdy units so cleaning is still a very reasonable option, but making sure there flushed etc before going back on protects the copper, but also prevents corrosive chemicals entering the heating system and damaging other components.

 

[SirLancelot]

Most small plates are a mixture of stainless steel and copper, the copper is there to give them a little flexibility when there undergoing thermal stresses, you need to be careful cleaning them as incorrect or overly strong chemicals could corrode the copper and cause the plate to leak. Although there pretty sturdy units so cleaning is still a very reasonable option, but making sure there flushed etc before going back on protects the copper, but also prevents corrosive chemicals entering the heating system and damaging other components.

You've touched on a significant consideration here.

(Again - this thread is meant to be an exploratory discussion).

If pin holes or small corrosive defects in the plate occur - would the CH and Tap water mix?

Could CH Inhibitor + some magnetite find its way into tap water? Would that be immediately apparent to the householder/user?

SOS - (if I'd understood things correctly) is a very corrosive chemical.

Others on the forum have mentioned that SOS bottles have warnings on the label, about it's use with certain metals?

More over, the fact that it is a toxic chemical - giving off fumes, it can also cause burns & can also react in some way with water (whilst cleaning) - has made me ponder about the risk/benefits of using to clean out PHEx's for domestic boilers.

I'm wondering if there is an established professional protocol for cleaning / repurposing Plate Heat Exchangers that provide kitchen water. I suspect it would specify the use of different chemicals - that were less corrosive?

I'd imagine at minimum it would require a post-cleaning pressure test, (after cleaning) - to ensure there is no cross contamination of the two water streams?

 

[gas112]

If the plate pinholes then this would show as a rise in boiler pressure on the gauge. As for mixing the incoming water pressure is more than what is in the system so any transfer would be tiny to none